450 ak help, please

[tommag]

I got my 450 ak and tried 3031 and RL7. The 3031 showed no pressure signs with the case full to the neck. (67.7 grs, 400 gr J-word, 1990fps) The RL7 started to flatten the primers with 61.5 grs and 400 J-word, 2027fps)
My cases are blown-out win348's with 92.9 grs water capacity to the top, 74.1 grs to the neck. the bbl is 18" long.
My problem is this: I have lots of milsurp IMR4895, but have no idea how to figure a starting load out. Since 4895 is slower than 3031 and RL7, maybe it wouldn't be a suitable powder, but I'd like to try, since I have plenty and $10/lb is lots cheaper than $19.
Does anyone know a formula to convert from one powder to another? Prior to this I've always followed the book and worked my way up, but recipes for this cal. are few and far between.
I've tried no cast for this, and probably won't for a couple of paychecks, but would like to try the Lee 500 gr Gc's.
Another thing, Cartridges of the world shows case length of 2.25" and Wildcats shows 2.145 max. .11" seems like quite a variance. I haven't done a chamber cast, but 2.193" works good in mine (trimmed just enough to square the case).
I'll be on the road for a couple of weeks, so thanks in advance. Tom

[Buckshot]

.............If a full case of 3031 shows no pressure, a casefull of 4895 which is slower yet won't get you into any trouble at all.

............Buckshot

[tommag]

What I think I get is- slower powder at the same weight is always lower pressure?

[Buckshot]

What I think I get is- slower powder at the same weight is always lower pressure?

...............Exactly. A casefull of 3031 in a 45-70 will get a 405 gr going 2100 fps or more, but a casefull of WC860 will get you 1000 fps with a powder littered bore.

.................Buckshot

[singleshotbuff]

Tom,

I have at home (I'm working right now) a Powley Slide rule computer. I've never used it, but from what I understand, it will give you a starting load for a cartridge & bullet weight with IMR powders based on case capacity. I think it will also provide and estimated velocity and chamber pressure. From what I have read in the past, the little jewels are amazingly accurate. If you'd like I can try to run your question through it and see what it says.

SSB

[tommag]

SSB, Thanks for the offer. The 3031 data I have came from a Powley Computer, and the article says it recomended 3031 for all bullet weights. I think Buckshot has me pointed in the right direction.
Tom